1. Field of the Invention
The present invention relates to an electronic apparatus, and more particularly, to an electronic apparatus comprising a regulator module that outputs driving power having voltage levels different according to whether an external device is connected thereto.
2. Description of the Related Art
Generally, an electronic apparatus using a battery, for example, a portable computer such as a laptop computer, a notebook computer, a personal digital assistant (PDA), etc a mobile phone, a compact disk (CD) player, a video camcorder, and so on has been widely used because it has advantages of portability and availability while being carried. Further, such a portable electronic apparatus can be connected to an adapter to receive commercial alternating current (AC) power as well as power from the battery.
Together with the development of the portable electronic apparatus, the importance of battery technology used in the portable electronic apparatus is looming large. Since power supply is necessary to the portable electronic apparatus while the portable electronic apparatus is being carried, the battery supplying the power to the portable electronic apparatus has been developed in regard to its charging capacity and use time. Further, there has been developed, various methods for increasing the use time of the electronic apparatus with respect to the battery having the same charging capacity. That is, there are various methods for minimizing power consumption of the electronic apparatus.
FIG. 1 is a control block diagram for illustrating a power supplying system of a conventional electronic apparatus. As shown therein, a conventional electronic apparatus 100 includes a system part 150 including a plurality of electronic components performing inherent functions of the electronic apparatus 100, a power supply 120 such as an adapter and/or a battery to supply power to the electronic apparatus 100, and a voltage regulator 130 to change the power supplied from the power supply 120 into driving power suitable for each electronic components of the system part 150.
Further, the electronic apparatus such as a portable computer comprises various connectors 160 to which various external devices 300 are connected. For example, the connector 160 includes a universal serial bus (USB) port supporting an USB interface.
Generally, the connector 160 supporting the USB interface or the like is standardized to supply the driving power from the voltage regulator 130 of the electronic apparatus 100 to the external device 300. For example, in the case of the USB interface, the power supplied from the electronic apparatus 100 to the external device 300 is standardized to have a voltage level of 5V, and the external device 300 such as a memory stick supporting the USB interface is manufactured by an external device manufacturer to be driven with a driving power of 5V.
Further, the electronic apparatus is manufactured by an electronic apparatus manufacturer to have the voltage regulator 130 that outputs a voltage level of 5V among various voltage levels to the external device 300 through the USB port, thereby adhering with the standard for supplying the power through the USB interface.
Meanwhile, the electronic components of the system part 150 receiving the power from the voltage regulator 130 have specification about the voltage level required for its own driving. Generally, an electronic component manufacturer allows a reference voltage level for optimum driving of the electronic components to leave a voltage margin of a predetermined percentage. For example, in the case of electronic components requiring a driving power of 5V, a voltage margin of about ±5% is left, so that the electronic component can be driven within a voltage range from the minimum voltage of 4.75V to the maximum voltage of 5.25V. Therefore, even though the power supplied from the voltage regulator 130 has an unstable voltage level, the electronic apparatus 100 can be stably driven.
In the case where the power does not have the voltage level of 5V, but a voltage level of between 4.75V and 5V is supplied to the electronic component while the electronic component is being driven, it is expected that power consumption be reduced corresponding thereto. That is, when the electronic apparatus 100 is manufactured, the electronic apparatus manufacturer can lower the voltage level of the power outputted from the voltage regulator 130 in consideration of the foregoing voltage margin of the electronic component. However, as illustrated in FIG. 1, when the power outputted from the voltage regulator 130 is supplied to the external device 300, the electronic apparatus manufacturer cannot consider the voltage margin of the external device, so that the external device 300 may operate unstably.
Accordingly, if the voltage level of the power outputted from the voltage regulator varies according to whether the external device 300 is connected to the electronic apparatus 100, power consumption is decreased when the external device 300 is not connected to the electronic apparatus 100, and the external device 300 operates stably when the external device 300 is connected to the electronic apparatus 100.